Australian Lucas Browne shows off the WBA world heavyweight title belt after beating Ruslan Chagaev in Russia in March. But a drugs test following the fight has shown up traces of Clenbuterol in Browne's sample

'Big Daddy' Browne stopped Ruslan Chagaev in the tenth round of the WBA world title bout in the Russian city of Grozny in March. It was the 21st knockout of his unbeaten 24 fight career

VADA's email to people involved in the Browne-Chagaev fight which took place in the Russian city of Grozny said: 'This letter is to advise you that the 'A' sample urine specimen number 2998060 collected from Lucas Browne ... has been analyzed (sic) for anabolic agents, diuretics, beta-2 agonists and stimulants.

'The results of the analysis are as follows: Adverse. Urine specimen contains clenbuterol.'

Clenbuterol is used as a metabolism booster as part of a fat-burning process.

Browne has the right to request a B-sample, however that must be done at his own expense.

WHAT IS CLENBUTEROL?

Clenbuterol is a stimulant drug that increases aerobic capacity and helps speed up the rate that body fat is metabolized.

It is sometimes used in the treatment of horses and to increase production of lean meat in cattle.

Although approved in some countries for use by asthma patients, it is on the World Anti-Doping Agency banned list for athletes.

WADA say: 'Clenbuterol is a prohibited substance and there is no threshold under which this substance is not prohibited'.

The drug has also reportedly been used by celebrities such as Britney Spears and Lindsay Lohan due to its alleged weight-loss properties.

Tour de France champion Alberto Contador was stripped of his 2010 title after testing positive for Clenbuterol.

Aussie cyclist Michael Rogers was suspended in 2013 for taking the drug although the sport's governing body, the UCI, accepted his claim that he had eaten contaminated meat.

Cronulla Sharks forward Reni Maitua returned a positive test for Clenbuterol in 2009 and was banned for two years, with Manly's Under-20 player Shane Gray handed the same punishment for the same offence.

Browne appeared on Nine's Footy Show on his return to Australia following his world title win in March and was pictured backstage with presenter Erin Molan

Browne, who played rugby league as a junior for Parramatta Eels, poses for a picture with former NRL star Beau Ryan who is now a TV celebrity on the Footy Show

The 36-year-old western Sydney fighter became the first Australian fighter to ever win a version of the heavyweight title with his victory over Ruslan Chagaev in March, but later tested positive for drugs

Browne is a former bouncer who grew up in Granville near Parramatta. He played junior rugby league for the Eels before starting cage fighting and then moving into boxing in 2009

Browne grew up in Granville, near Parramatta, and played junior rugby league for the Eels before working as a bouncer in western Sydney for 13 years.

He then took up cage fighting, but began his professional boxing career in 2009 with a win over Jason Kier at the Manly Leagues Club.

Since then he has not tasted defeat in any of his 24 fights, beating former three-weight world champion James Toney in 2013 to really put himself on the international map.

The man known as Big Daddy is promoted by British boxing legend Ricky Hatton and, following his superb win over Chagaev, had his sights set on a massive payday with a possible clash against WBA super champion Tyson Fury.

But if his positive drugs test is upheld, Browne will be stripped of his world title and faces a lengthy ban from the sport.

Aussie fighter Lucas Browne meets popstar Jessica Mauboy at an event one week after his successful WBA world heavyweight title fight against Ruslan Chagaev in Russia

Browne, 36, also won the WBC Eurasia Pacific Boxing Council heavyweight title in 2014 when he beat American Chauncy Welliver at the Hisense Arena in Melbourne